1. Field
Embodiments relate to a power supply control apparatus of an electric device to reduce standby power to be supplied to the electric device in a standby mode of the electric device.
2. Description of the Related Art
Recently, as analog and digital technologies make rapid progress, electronic products with up-to-date functions have rapidly come into wide use in homes and workplaces.
The increase in number of such electronic products increases use of power. Particularly, even in the case where a home appliance used in daily life, such as a microwave oven, an air conditioner or an air cleaner, is not in use, an operating voltage may be applied to a printed circuit board (PCB) including various detectors installed in the home appliance immediately after the home appliance is plugged in, resulting in continuous consumption of certain standby power even in a standby state.
The standby power is power consumed when an electric device doesn't perform a main function thereof or waits for an internal or external turn-on signal under the condition that it is connected to an external power source (AC power source).
A television, an air conditioner, a microwave oven, a computer, a mobile phone charger, or the like is a product that consumes a larger amount of power in a standby state where it is connected to the power source even though they do not perform their natural or main functions. Considering how many hours a day a household microwave oven is used, it is easy to see that standby power can contribute to significant waste of energy.
Such an electric device performs a power saving standby mode when it is not used under the condition of being connected to the commercial AC power source. At this time, the electric device may not be completely disconnected from the power source, thus generating standby power of several hundred milliwatts (mW) or several watts (W).
Particularly, in an electric device capable of being remotely controlled by a remote controller, such as a television, an air conditioner or an audio device, minimum power must be supplied to a controller including a remote control signal receiver even if the electric device is stopped in operation. This allows the electric device to receive a remote control signal transmitted from the remote controller and perform a corresponding function when the user operates the remote controller to control the electric device in stop.
For this reason, the electric device capable of being remotely controlled by the remote controller generates a certain amount of standby power to receive a signal from the remote controller in the standby mode.
This standby power accounts for about 11% of domestic household power consumption. In order to reduce the standby power, national sanctions have been applied and a variety of technologies have been developed.
Conventional approaches to reducing the standby power may include a technology to improve efficiency of power in voltage conversion of an existing transformer, and a technology to supply the standby power using an auxiliary power supply, instead of the transformer.
The power efficiency improvement technology is to rectify AC power supplied from a commercial AC power source, supply the resulting voltage to the transformer, convert the voltage to the transformer by intermittently controlling a switching element, and then supply the resulting power for use as the standby power.
Most of the standby power consumed by an electric device is consumed by a remote controller signal receiving circuit to receive a power control signal from a remote controller in the standby mode or by a circuit to receive a power control signal from an external power button. Here, the consumed power is very small. However, when a switched-mode power supply (SMPS), which is used to supply such power, supplies a voltage much lower than a rated voltage, efficiency thereof decreases dramatically, thereby causing power loss to occur by the internal transformer. In this regard, technologies to improve standby mode efficiency of the SMPS have been developed, but, practically, it is very difficult to realize low power on the order of several mW.
Technology to supply standby power using the auxiliary power supply, instead of the transformer, charges a secondary battery or a super capacitor with separate power and uses the charged power as the standby power in the standby mode.
In this case, the charged power is used instead of the normal standby power in the standby mode. However, there may be a limitation in an amount of power to be stored in the secondary battery or the like, requiring recharging of the secondary battery or the like after the lapse of a certain time. Also, if the secondary battery fails to be recharged, it may be discharged completely, thereby making it impossible to guarantee normal operation of the electric device.